Synthetic plastic molding form



Oct. 4, 1965 JONSSQN ET AL 3,276,176

SYNTHETIC PLASTIC MOLDING FORM Filed April 23, 196-3 5 Sheets-Sheet 1FIGZ K. A. JONSSON ET AL SYNTHETIC PLASTIC MOLDING FORM Oct. 4, 1966 5Sheets-Sheet 3 Filed April 23. 1963 Oct. 4, 1966 K. A. JoNssoN ET3,276,176

SYNTHETIC PLASTIC MOLDING FORM 5 Sheets-Sheet 5 Filed April 25, 1963FIG. 5b

FIG. 5Q

FIG.6

United States Patent 3,276,176 SYNTHETIC PLASTIC MOLDING FORM Karl AxelJonsson, Alvsjo, and Ludvig Horwitz, Valllngby, Sweden, assignors toIngenjorsfirman Orrje & Co.

AB, Stockholm, Sweden Filed Apr. 23, 1%3, Ser. No. 275,090 Claimspriority, application Sweden, May 8, 1962, 5,176/62; May 24, 1962,5,838/ 62 8 Claims. (Cl. 52309) The present invention relates generallyto a building element for use within the house building technics as wellas within civil engineering and similar fields. Generally speaking itcould be said that the subject of this invention can be used in allconnections where in a construction containing concrete or some similarmouldable material there is need of a moulding form which without anyharm can be incorporated with the finished construction.

In the above-mentioned technical fields there is often a need for thecreation of hollow spaces, voids or apertures for the reception ofdetails which must, or preferably should, be mounted only uponsolidification of the concrete. By way of example, reference can be madeto such passages in concrete framings and walls etc. which are to betraversed by pipes, conduits, electrical cables and so on. Anothertypical case relates to the anchoring in the concrete construction ofarticles which in consequence of their own weight or due to externalinfluence cause forces tending to pull them out from the solidifiedconcrete mass. As an example of the last-mentioned case, reference canbe made to the mounting of rails, steel beams and the like, especiallyin the undersurface of a concrete construction.

Prior to this invention the moulding forms necessary for the purposesabove exemplified were generally made of wood, assembled at their placesof installation and there matched to the actual requirements. It isoften desired to re-fill with concrete that portion of the space definedby the form which remains when the pipe, the anchoring member or thelike has been mounted. However, in order then to attain bonding with theoriginal, outer concrete mass, the wooden form first has to be removed.This involves several drawbacks. Firstly, it means an additional workingoperation requiring comparatively long time and, secondly, the removalof such a form is not seldom difficult which in turn often leads to theadoption of such tools or methods, respectively, that adjacent portionsof the concrete are damaged.

' Especially in the case of concrete beams, these damages maynecessitate extensive and expensive repair work and, in certain cases,the damages are of such a nature that no reparation at all can be made.A third major disadvantage is that, after the wooden form has beenremoved, the hollow space which it has created contains remains thereof,especially in the form of wooden fibres adhering to the walls of thespace. Naturally, this means that the contact, and consequently thebonding, between the two concrete masses becomes unsatisfactory.Finally, it should be pointed out that even if none of the disadvantagesabove enumerated would actually occur, that drawback is always presentthat in the finished construction the concrete mass inside the form mustfrom a stress-resistance point of view be looked upon as a more or lessseparate body which, when subjected to sufliciently large externalstresses, can be forced out from the surrounding concrete mass. Inaddition thereto, the fact that the moulding forms are made at theirplace of installation means that they become comparatively expensive andalso that some of the employees of the builder must be delegated tocarry out this work which is disadvantageous already in view of thecontinuously increasing demand for as short a construction time aspossible.

The main object of the invention is to provide a building element whichis cheap in manufacture and use, has very good strength and chemicalresistance and can simply be given at least the majority of all thedimensions which such elements may assume.

A special object of the invention is, in a moulding form constituting awall of separation between two moulded masses which are presumed tobecome subjected to external forces oriented in dilferent directions, tomake the form adapted to prevent said forces from severing the twomoulded masses.

Generally stated, a moulding form according to this invention ischaracterized thereby that it consists of a synthetic material resistantagainst concrete, earth and the like, preferably a plastic, andconstituted by a prefabricated, hollow body which is composed of one ormore sections, has a varying cross-section and is intended to bepermanently incorporated into a building construction through mouldingagainst at least a portion of the one side of its walls.

Additional objects and advantages of the invention will appear from thefollowing description of some preferred embodiments thereof when read inconjunction with the accompanying drawings, in which:

FIGURE 1 is a view in elevation, with parts broken away, showing abuilding element according to a first embodiment of the invention;

FIGURE 2 shows a horizontal view of the element in FIGURE 1;

FIGURE 3 illustrates a special use of building elements according to twofurther embodiments of the invention;

FIGURE 4 shows a building element according to a fourth embodiment ofthe invention;

FIGURES 5a and 5b illustrate how, in accordance with a special featureof the invention, building elements of different cross-sectional areasand shapes can be made through combination of standard sections;

FIGURE 6 is a perspective view in a larger scale than FIGURE 5 showinghow the sections in FIGURE 5 can be joined to each other;

FIGURE 7 shows a building element according to FIG- URE l or 4 installedin a concrete layer, and

FIGURE 8 shows a section in a plane perpendicular to the plane of thesection in FIGURE 7.

The building element illustrated in FIGURES l and 2 consists of anintegral tubular body 3 of rectangular cross-section and with undulatorycorrugated walls. Preferably, the wall material of the element is somesuitable plastic, e.g. polystyrene or some other plastic of thepolymerisation type. As appears from the drawing, the Wall thickness issmall in relation to the cross-section of the element. This feature doesinter alia involve that the element can conveniently be manufactured atsubstantial length and then, at the building site by the use of simpletools, e.g. a saw, easily divided into shorter pieces to meet the actualneeds. Preferably, the undulations 1 are made according to a modulesystem. On the other hand, in spite of the comparatively small wallthickness, thanks to the presence of the undulations, the element is notonly rigid in itself but, in addition thereto, it can without the aid ofany auxiliary supporting means withstand the very considerable forceswhich may arise when it is used as a moulding form, e.g. in a concreteconstruction. Obviously, as a rule these forces are greatest when thefirst moulding takes place against the outer 'walls of the element.

In FIGURE 3 there are shown two building elements 3 moulded into aconcrete construction 2. The left hand element has corrugations 1 oftriangular cross-section, while the corrugations of the right handelement are of rectangular profile. In other respects these two elementsdo principally correspond to the one shown in FIGURE 1. Generally, thesinusoidally undulated profile is preferable because the costs formaking the tools necessary for the manufacture of the elements are thenlower.

According to the embodiment of the invention shown in FIGURE 4, thebuilding element 3 is of circular crosssection and made in two halves,3a, 3b, the joints of which are located in a diametral plane. At theirabutting edges each element half is provided with radially outwardlyextending flanges 4, the detailed configuration of which is most clearlyshown in FIGURE 6. As shown therein, these flanges have holes and pins,which can be brought into locking engagement. The pins have beendesignated by reference numeral 5 and the holes by numeral 6. As doesalso most clearly appear from FIGURE 6, the one flange 4a of eachelement half 3a and 3b is provided with pins only, whereas the otherflange, 411, has only holes. In addition to these holes 6, all flangeshave pairwise registering holes 7 which are provided for the purpose offacilitating the fixation of the moulding form before the mouldingoperation. That fixation can by way of example be made by means of metalwires 8 which are inserted through the holes 7 as shown in FIGURE 4.

The element illustrated in FIGURE 4 does in two further respects deviatefrom the embodiments earlier described. The one difference consists inthe presence of axial ridges 9. These do on the one hand serve asstiffening means for the finished moulding form and, on the other hand,they do during the manufacturing of the form promote uniformdistribution of the plastic material in the matrixes or similar tools,in which the form halves are made. The second difference is that theelement has been provided with discs, or lids, 10 and 11 making itpossible to close its ends. That possibility is of great value forseveral reasons. One advantage is that by means of the end discs it canbe guaranteed that the interior of the element is completely protectedfrom impurities during all working steps which precede the pouring ofconcrete into the in- ,terior of the form. Another advantage is that itbecomes possible omnilaterally to surround the element with e.g.concrete.

FIGURE 4 does also show that discs 10 and 11 are 'convex outwardly.Thereby it is attained that when the discs are subjected to an externalpressure, the forces generated by that pressure do only tend to pressmore firmly against the element proper. Suitably, the diameter of thediscs is chosen in such a manner that they fit in the element when eachof its end surfaces are located in a plane corresponding to the minimumdiameter of the element.

FIGURE 5a ilustrates how the cross-sectional area of the element can beincreased through the introduction of corrugated but uncurved wallportions 12 between the two halves 3a and 3b. In the embodiment of theinvention shown in FIGURE 5b no less than three such additional wallportions 12, 12 and 12 have been inserted between the two curved elementhalves 3a and 3b. Sections 12, 12, 12" do of course also have flanges 4and fastening means in the form of holes and pins. In this context itshould be emphasized that this method of joining the different sectionsof the element has been chosen for the purpose of illustration only andcan be supplemented with or replaced by other methods, such as glueing.

In FIGURE 7 there has been shown a building element according to FIGURES1 or 4 installed in a concrete layer 2 containing reinforcing rods 13.The interior of the element is likewise filled with a mass of concrete14 which has been poured after hardening of the concrete in layer 2..The purpose of the construction is to make possible such a subsequentmoulding of a smaller concrete body which shall retain an anchoringmember 15 that is presumed to become subjected to great forces tendingto pull it out of the concrete. As appears from the figure, thanks tothe corrugated shape of the surface separating the two concrete bodies,these forces are effectively transferred to, and thus absorbed by, thelarger reinforced concrete layer 2. Before the concrete moulding takesplace a so-called mounting-rod 16 is inserted through holes 17 in thewalls of the element 3. The hook-like lower end of member 15 gripsaround rod 16 inside the form 3. In this way it is possible to holdmember 15 fixed in its correct position during the moulding andhardening of the concrete.

FIGURE 8 does principally correspond to FIGURE 7 but shows a section ina plane perpendicular to the plane of section in FIGURE 7. In additionthereto the anchoring member 15 is directed downwards and the mountingrod has been omitted.

Finally, it should be underlined that the embodiments of the inventionshown on the drawing and above described are only meant to illustratethe general principle thereof. A variety of different modifications canbe made as far as the shape of the element proper is concerned as wellas relating to the means for assembling the sections of the element andfor fixing the latter in its desired position. As an example of amodification of the first-mentioned type it could be mentioned that thepitch of the corrugations need not be constant in one and the sameelement. While it is true that the invention makes it possible toproduce building elements of relatively great length there can incertain cases still be desirable to connect two or more elements axiallyafter each other. For that purpose any suitable means can be used, suchas internal or external jointing sleeves. In the end it should bepointed out that the expression building element as used here shall beconstrued in its widest sense. To illustrate this fact it could bementioned that an element in accordance with the present invention canbe used as a moulding form for the mounting of poles for fences, trafficsigns and the like.

What we claim is:

1. A molding form for use in the formation of concrete structures,comprising: a synthetic plastic tube having corrugated walls, saidplastic being resistant to concrete and earth, and integrally-formedflanges, extending parallel to the axis of said tube and radially fromthe exterior walls of said tube, having apertures formed therein adaptedto receive wires for holding said form in place during concreteformation.

2. A molding form in accordance with claim 1 wherein .the tube isrectangular in cross-section.

a portion of the concrete formation operation.

5. A molding form in accordance with claim 1 wherein the tube includesat least two side sections mechanically coupled together to form saidtube.

6. A molding form in accordance with claim 5 wherein the tube includesat least one pair of opposed, fiat side panels coupled between twosemiacylindr-ica-l sections to provide a tube of oblong cross-section.

7. A molding form in accordance with claim 5 wherein each section hasformed along its edges a portion of the flanges and said portions formsaid flange when said sections are coupled together.

8. A moulding form in accordance with claim 7 wherein one portion of theflange has second apertures which are cooperatively engageable with pinsformed at complementary points on the other portion of said flange.

References Cited by the Examiner UNITED STATES PATENTS 995,008 6/1911Jackson 52-302. 1,045,562 11 1912 Kennedy 52-6-99 1,070,807 8/1913Hereford 138-173 X (References on following page) UNITED STATES PATENTSSchodde 28542 X Gfiesler 22072 X Phillips 52--302 X Harris 22072 XLeontovich 52-30 3 3 Whitlock 52302 X 6 2,728,356 1-2/1955' Brimsmade eta1 138 121 2,957,279 10/ 19 60 MoNair 52701 3,065,576 1 1/ 196 21Prizle; et a1 52- 6 12 5 F RANK L. AB'BOTT, Primary Examiner.

CHARLES E. OCON-NELL, Examiner.

D. R. CO-MMUZZIE, M. O. WAR NECKE,

, Assistant Examiners.

1. A MOLDING FORM FOR USE IN THE FORMATION OF CONCRETE STRUCTURES,COMPRISING: A SYNTHETIC PLASTIC TUBE HAVING CORRUGATED WALLS, SAIDPLASTIC BEING RESISTANT TO CONCRETE AND EARTH, AND INTEGRALLY-FORMEDFLANGES, EXTENDING PARALLEL TO THE AXIS OF SAID TUBE AND RADIALLY FROMTHE EXTERIOR WALLS OF SAID TUBE, HAVING APERTURES FORMED THEREIN ADAPTEDTO RECEIVE WIRES FOR HOLDING SAID FORM IN PLACE DURING CONCRETEFORMATION.